Feature>>>Audio dock is a ultra-portable, battery operated mini stereo system that plays music from your mobile phone, MP3, MP4, PC, iPod and other audio devices with a 3.5mm audio jack >>>Output power: 3W >>>Built-in rechargeable polymer battery lasts up to 6 hours of continuous use >>>ON/OFF switch to save battery life while not in use.>>>Audio dock could be charged in PC with USB cable, or by a charger